The present invention relates to a laminated board product that can be converted into containers for carrying canned or bottled beverages or for various folding carton applications. More particularly, the final product has sufficient wet strength properties for use as the beverage carrier, or carrier board, product mentioned above. The laminate board product is repulpable and recyclable.
U.S. Pat. No. 5,882,746 discloses a laminated paperboard package that is produced by initially printing graphics by high speed printing on a sheet of clay-coated publication paper. The pre-printed paper is then continuously applied to the surface of a cellulosic substrate and bonded to the substrate, preferably through the use of starch as an adhesive, to provide a laminated product. This structure has several disadvantages in that there is no ability to print beverage carrier designs on existing print stations that are set up for printing heavy boards which are characteristic of beverage carriers. In addition, some printing presses are equipped to cut the printed material into cartons in an on-line after printing procedure. A pre-printed paper laminated to a board would require an additional cutting operation for such printing presses. This pre-printed concept is essential to the patent""s disclosure and clearly distinguishes same from the subject matter contained herein.
It is an objective of the present invention to produce a final product that has sufficient wet strength properties even though the original paper and/or paperboard components do not have wet strength additives in them.
It is also an objective of the invention to have a structure that allows for lower coat weights on the coated sheet and still allow one to get the desired opacity compared to standard clay coated unbleached grades.
It is a further object of the present invention to produce a laminated board grade that can be used for beverage carriers and/or unbleached or bleached folding carton applications.
The product produced from the laminated board structure of the present invention, includes as a paperboard substrate, unbleached or bleached board, containing either Kraft, groundwood, thermomechanical (TMP), chemithermomechanical (CTMP), bleached chemithermomechanical (BCTMP), and/or recycled fiber. Laminated to the board substrate is a lightweight coated or uncoated, unprinted, white, paper which, if coated, is coated on one, or two sides. This produces a product with a smooth unprinted surface for high quality graphics post-printing. Lamination can occur either by standard adhesive (aqueous-based, solvent-based, or UV-cured) lamination, pasting methods, use of an extruder, or through a hot melt application system.